One of the most challenging topics facing the prospect of realized drug delivery via nanomaterials is the controlled release of a specific drug as desired. This critical “triggering” of a drug manifests itself in a plethora of ways: spatially, temporally, and dosage precision. To cause release, many different approaches have been undertaken; stimuli-responsive materials which respond in the presence of heat, pH, light, enzymes, magnetic field, or electric field can be used.